RESUMO
Muscle glycogen concentration (MGC) and lactate (LA), activity of glycogen debranching enzyme (GDE), glycogen phosphorylase (GP) and adenosine monophosphate kinase (AMPK) were determined at 0.5h (T0) and 24h (T24) post-mortem in Longissimus dorsi samples from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24h postmortem. MGC, LA and glycolytic potential were higher (P<0.05) in normal pH carcasses. GDE activity was similar (P>0.05) in both pH categories. GP activity increased between T0 and T24 only in normal pH carcasses. AMPK activity was four times higher in normal pH v/s high pH carcasses, without changing its activity over time. Results reinforce the idea that differences in postmortem glycogenolytic/glycolytic flow in L. dorsi of steers showing normal v/s high muscle pH at 24h, could be explained not only by the higher initial MGC in normal pH carcasses, but also by a high and sustained activity of AMPK and an increased GP activity at 24h postmortem.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Sistema da Enzima Desramificadora do Glicogênio/metabolismo , Glicogênio Fosforilase/metabolismo , Glicogênio/metabolismo , Glicólise/fisiologia , Carne/análise , Músculo Esquelético , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Bovinos , Humanos , Concentração de Íons de Hidrogênio , Masculino , Músculo Esquelético/química , Músculo Esquelético/enzimologia , FosforilaçãoRESUMO
This study was conducted to determine the use of repeated transvaginal ultrasound-guided cumulus oocyte complex (COC) aspiration on COC recovery rate, in vitro embryo production (IVP) and subsequent pregnancy rates in Holstein Friesian (HF) and Aberdeen Angus (AA) cows (Experiment 1), and in pregnant and non-pregnant Holstein Friesian cows (Experiment 2). Cycling, non-pregnant HF (n=17) and AA (n=32) cows with 40-70 days postpartum, between 3 and 5 years of age were used in the Experiment 1. All cows were submitted to repeated transvaginal ultrasound-guided COC aspiration twice a week for 5-7 weeks. Cumulus ooctye complexes (COC) were in vitro matured, fertilized and cultured for 8 days. An overall of 100 and 350 embryos from HF and AA cows respectively were cryopreserved using a conventional slow freezing (Experiment 1). A total of 81 and 285 frozen-thawed embryos from HF and AA cows respectively were transferred to recipient cows. Pregnancy diagnosis was performed at 60 and 150 days of gestation using transrectal ultrasonography. In Experiment 2, cycling non-pregnant (n=9) and pregnant (n=8) HF cows were submitted to repeated ultrasound-guided COC aspiration and COC were in vitro matured, fertilized and cultured as in Experiment 1, except that embryos were cryopreserved but not thawed and transferred as described for Experiment 1. The results of this study indicate that COC recovery rate and blastocyts production are affected by the breed of the donor cow. The quality of blastocyts produced from both breed did not differ in terms of pregnancy and calving rates (Experiment 1). The physiologic state of pregnancy did not affect COC recovery rate and blastocysts production per donor/session (Experiment 2). The use of ultrasound-guided COC aspiration and IVP could be a powerful technique to improve the genetic of beef and dairy cattle managed under pasture-based conditions management in the southern Chile.
Assuntos
Bovinos/fisiologia , Fertilização in vitro/veterinária , Recuperação de Oócitos/veterinária , Oócitos/fisiologia , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/fisiologia , Animais , Transferência Embrionária/métodos , Transferência Embrionária/veterinária , Feminino , Fertilização in vitro/métodos , Lactação , Recuperação de Oócitos/métodos , Gravidez , Ultrassonografia/métodos , Ultrassonografia/veterináriaRESUMO
OBJECTIVE: (1) To compare the effect of an alcohol-free Mediterranean-type diet (MD) and a high-fat diet (HFD) on variables of primary haemostasis (bleeding time, plasma von Willebrand factor and platelet aggregation/secretion). (2) To test whether red wine supplementation modified these variables, independently of the diet. DESIGN, SUBJECTS AND INTERVENTION: Controlled prospective intervention study. Two groups, each consisting of 21 healthy male university students (22+/-3.4 y), received either MD or HFD during 90 days. Between days 30 and 60, both diets were supplemented with 240 ml/day of red wine. Baseline (T0) and T30, T60 and T90-day samples were drawn. Bleeding time was measured before (day 30) and after (day 60) wine supplementation. No drop out from the study was experienced. SETTING: University campus and outpatient nutrition clinic. RESULTS: All baseline (day 0) variables did not differ significantly between study groups. On day 30, individuals on MD had significantly higher levels of plasma beta-carotene, folate, ascorbate, and eicosapentaenoic acid in plasma lipid fractions, than those on HFD. Total plasma cholesterol, HDL and LDL did not change significantly in either study group at any time point. After 30 days on each diet, individuals on MD had longer bleeding time (BT) than those on HFD (7.6+/-2.8 vs 5.8+/-1.7 min; P=0.017). BT did not change significantly after I month of wine supplementation (7.1+/-2.0 vs 5.5+/-2.0 min, respectively). Plasma von Willebrand factor (vWF : Ag) on day 0 was 89+/-40 and 111+/-70% in MD and HFD groups, respectively (P=0.21). These values did not change significantly at 30, 60 or 90 days. MD intake was associated with an increase in platelet serotonin secretion (P=0.02) and a marginal increase in platelet aggregation after stimulation with epinephrine (P=0.07). Wine intake resulted in a marginal decrease in platelet (14)C-5-HT secretion with 4 micro M ADP (P=0.07). However, both platelet aggregation and secretion were consistently increased when using collagen as agonist (1 and 2 micro g/ml, P=0.01). CONCLUSION: The longer BT in individuals on MD, obtained independently of red wine, denotes less interaction of platelets with the vascular wall, which could be beneficial from the point of view of cardiovascular (CV) risk. This effect is not explained by changes in the measured haemostatic determinants of BT (plasma vWF, ex vivo platelet function), and might be attributed to other as yet unknown vascular factors. Moderate consumption of red wine results in a significant increase in ex vivo platelet aggregation and secretion after stimulation with collagen. This observation contradicts previous reports, although further studies are required to elucidate the influence of this finding on CV risk.
Assuntos
Dieta Mediterrânea , Gorduras na Dieta/administração & dosagem , Hemostasia/fisiologia , Vinho , Adulto , Tempo de Sangramento , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Colágeno/farmacologia , Hemostasia/efeitos dos fármacos , Humanos , Lipídeos/sangue , Masculino , Agregação Plaquetária/efeitos dos fármacos , Agregação Plaquetária/fisiologia , Estudos Prospectivos , Fatores de Risco , Serotonina/metabolismo , Vinho/análise , Fator de von Willebrand/análiseRESUMO
BACKGROUND: Free radical-mediated oxidative damage is a known initial event in atherogenesis. Cardiovascular disease is frequent in the Chilean population showing differences in the prevalence of risk factors of the disease according to socioeconomic level (SEL). AIM: To determine levels of antioxidants and lipid peroxides in Chilean women from different SEL. PATIENTS AND METHODS: Blood samples were taken from 81 women for measurements of plasma ascorbic acid, beta-carotene, alpha-tocopherol, licopene, ubiquinol, glutathione, total plasma antioxidant capacity, and lipid peroxides (TBARS). RESULTS: Individuals in the lower SEL showed reduced levels of plasma beta-carotene, ascorbic acid, alpha-tocopherol, and ubiquinol compared to women in the higher SEL. There were no differences between groups in the plasma levels of glutathione, total antioxidant capacity, or TBARS. CONCLUSIONS: The results could be explained in part by the higher consumption of fruits and vegetables in women from the upper SEL.
Assuntos
Antioxidantes/análise , Peróxidos Lipídicos/sangue , Adulto , Idoso , Análise de Variância , Ácido Ascórbico/sangue , Distribuição de Qui-Quadrado , Chile , Feminino , Glutationa/sangue , Humanos , Pessoa de Meia-Idade , Fatores Socioeconômicos , Ubiquinona/sangue , Vitamina E/sangue , beta Caroteno/sangueRESUMO
Hyperhomocysteinemia in association with vitamin B(12) deficiency, and increased platelet aggregation, probably due to dietary lack of n-3 fatty acids, constitute cardiovascular risk factors frequently observed in vegetarians. We tested if administration of vitamin B(12) normalizes the concentration of total plasma homocysteine, and if intake of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) fatty acids modulates platelet function in a population of lactoovovegetarians. One week after a single intramuscular injection of cyanocobalamin (10000 microg) in 18 individuals, serum vitamin B(12) increased from 149+/-63 pg/mL to 532+/-204 pg/mL (p<0.0001) and total tHcy dropped from 12.4+/-4.7 to 7.9+/-3.1 micromol/L (p<0. 0001). Ten of fourteen of these vegetarians completed an 8-week supplementation with 700 mg/day of each eicosapentaenoic and docosahexaenoic acids. Increased incorporation of these fatty acids into plasma lipids was observed in all of them, together with a significant reduction in maximum percentage or slope of platelet aggregation with all the agonists tested (ADP, epinephrin, collagen, arachidonic acid). No significant change in bleeding time was observed after n-3 fatty acid trial. Supplementation with vitamin B(12) and n-3 fatty acids corrects hyperhomocysteinemia and reduces platelet reactivity to agonists in vegetarians. Whether this supplementation improves the already reduced cardiovascular morbidity and mortality associated with vegetarian diet has yet to be demonstrated.
Assuntos
Doenças Cardiovasculares/dietoterapia , Dieta Vegetariana/efeitos adversos , Adulto , Doenças Cardiovasculares/prevenção & controle , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/farmacocinética , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/farmacocinética , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-3/farmacocinética , Feminino , Humanos , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/etiologia , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Fatores de Risco , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Vitamina B 12/farmacocinéticaRESUMO
An intervention study was performed to evaluate the influence of a Mediterranean diet, a high fat diet, and their supplementation with red wine in moderate amounts, on biochemical, physiological, and clinical parameters related to atherosclerosis and other chronic diseases. For 3 months two groups of 21 male volunteers each, received either a Mediterranean diet or a high fat diet; during the second month, red wine was added isocalorically, 240 ml/day. Participants were kept under close medical and nutritional surveillance. At days 0, 30, 60 and 90, clinical, physiological and biochemical evaluations were made. Plasma vitamin C was significantly decreased in the high fat diet group compared to the Mediterranean diet group. After wine supplementation to the Mediterranean diet, a significant 13.5% increase in plasma vitamin C was observed. Furthermore, when wine was added vitamin E decreased significantly in plasma, 15% in the high fat diet and 26% in the Mediterranean diet. Total plasma antioxidant capacity (total antioxidant reactivity) increased 28% above basal levels in the Mediterranean diet group, but not in the high fat diet group. In both groups, wine induced a marked increase in total antioxidant reactivity above basal levels, 56% and 23%, respectively. Oxidative DNA damage, detected as 8-hydroxydeoxyguanosine (8-OHdG) levels in blood leukocyte DNA, was markedly increased by the high fat diet; however, it was strongly reduced, to approximately 50% basal values, after wine supplementation, both in the high fat diet and Mediterranean diet groups. Endothelial function, evaluated noninvasively as flow-mediated vascular reactivity of the brachial artery, was suppressed by the high fat diet, and was normal after wine supplementation. These effects are attributed to oxidative stress associated with a high fat diet, and to the elevated plasma antioxidant capacity associated with wine consumption and the Mediterranean diet. The results presented support the following conclusions: a high fat diet induces oxidative stress; a diet rich in fruits and vegetables enhances antioxidant defenses; wine supplementation to a high fat or a Mediterranean diet increases plasma antioxidant capacity, decreases oxidative DNA damage, and normalizes endothelial function.